We are now surfing an old f2 slalom comet 315 and looking for a second board with about 115-125 liters for me and my children. I am an intermediate surfer, my children (age 15 and 9) are learning/beginners. Our sails range from 3.5 m2 to 7.0 m2 (3.5, 4.8, 6.0, 7.0).

When looking for possible boards I often find recommended sail ranges, often higher than my sails are (for example 5.5-8.5 m2). I would like to know the reason for these recommendations.

My little daughter has now on the comet 315 a problem with going upwinds with her small sail. I think the reason is just that the boom of this sail is too short even with the most rear position of the mast.

Will we have the same problem with a new board when the recommended sail range is only higher than 5.5 m2? Could a smaller fin really solve this problem?
Or is there no correlation between board length and shape and the sail range?

The sailrange is an indicator of what sailsizes the board can carry for an avarage, adult, surfer. So you needn&#39;t look at the range and consider your little girl to fit it. The sailrange is also an indicator of what windrange the board can handle. The more wind the less controle you have over your board, so if the minimum sail is e.g 5.0 mé, you can always go lower, but you need to bare in mind that at a certain point you&#39;ll have too muych wind for the board and it goes downwind without you having any controle over it, which can be very dangerous.
If you are looking for a board of about 120 L and a big sailrange, i suggest you look at the SB carve. The 122 has a recommended range of 5.1-8.0, so it should easily be compatible with the 4.8-7.0 sails you have and your daughter can still go on it with her bigger sails if she&#39;s learning. Once she gets the hang of it and goes for bigger sails she should still be able to use the board.
Another option could be the S-type 115, but you may find it much harder to ride then a carve. However, the s-types sailrange is much more like your current sailrange.